Abstract

Cohesion (c) and friction (φ) angle are the two key parameters required in numerical simulations and designs of underground openings, excavations, and foundations in rocks. The paper discusses a simple method, based on a theoretical framework, to determine the two parameters from uniaxial compression test and indirect tensile strength test. Laboratory tests were carried out on 35 rock specimens and the values of c and φ were computed. The predicted values of c appear to be more realistic than those of φ, and the scatter is attributed to the anisotropy and heterogeneity generally observed in the rock cores. The computed value of c is 1·82 times the indirect tensile strength (σt).